Tonight, Couloir (www.couloir.ca) gives the World Premier of Jocelyn Morlock’s “Three Mediations on Light” at Music On Main’s “Modulus Festival” (www.musiconmain.com). In addition, take in performances of ukrainian composer Valery Kikta’s “Sonata for Cello and Harp” and New York based Nico Muly’s “Clear Music” (for Cello/Harp/Celeste).